The hitherto rarely used multicomponent Radziszewski reaction was applied to synthesize imidazoliumcontaining polymers under mild conditions with industrial feasible monomers. The polymerization process proved to be very efficient, yielding highly pure water-soluble polyimidazolium salts (PIMs) in one step. Reaction parameters were studied, and concentration and molar ratio of the starting materials were identified as important parameters for molecular weight control. Surprisingly, it was found that nonstiochiometrical ratios of the starting materials can be used to obtain high molecular weight PIMs. Polymerization using different amine monomers demonstrated the broad scope of the poly-Radziszewski reaction. PIMs containing hydrophilic, hydrophobic, or even zwitterionic moieties were accessible via the simple one-step procedure.

Oligo-ethylene glycol-containing dendronized monomers MG1, MG1.5, MG2, and MG3 were synthesized in a particularly easy fashion on the gram scale involving only few steps. Their corresponding homopolymers (PG1, PG1.5, PG2, and PG3) and copolymers (PG1co2, PG1co3, and PG2co3) were synthesized via free radical polymerization. All the polymers are soluble in water and also in organic solvents such as DCM, CHCl 3 , 1,4-dioxolane, DMF, and DMSO. Their glass transition temperatures (T g ) are in the range −68°C < T g < −48°C and thus rather low. All polymers show thermoresponsive behavior which was investigated by turbidity measurements. Interestingly, a 1:1 mixture of homopolymers PG1 and PG2 behaves identical with PG1 alone, while the collapse curve of copolymer PG1co2 is almost superimposable with that of PG2 alone. Thus, in the former case PG1 dominates the thermoresponsive behavior while in the latter this is done by the G2-dendrons in the copolymer. Finally, the polymer chains were visualized by AFM, confirming the rod-like behavior of these rigidified polymers.

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Being the major renewable source of bio-aromatics, lignin possesses considerable potential for the chemical industry as raw material. Kraft lignin is a couple product of paper industry with an annual production of 55,000,000 ton/y and is considered the largest share of available lignin. Here we report a facile approach of Kraft lignin depolymerization to defined oligomeric units with yields of up to 70 wt.%. The process implies utilization of an aqueous base in combination with a metal containing catalyst and an alcohol under non-oxidative atmosphere at 300 °C. An advantage of the developed approach is the facile separation of the oligomer product that precipitates from the reaction mixture. In addition, the process proceeds without char formation; both factors make it attractive for industrialization. The suppression of the repolymerization processes that lead to char formation is possible when the combination of metal containing catalyst in the presence of an alcohol is used. It was found that the oligomer units have structural features found in phenol-acetaldehyde resins. These features result from the base catalyzed condensation of lignin fragments with in situ formed aldehydes. Catalytic dehydrogenation of the alcohol provides the latter. This reaction pathway is confirmed by the presence condensation products of Guerbet type reactions.

Composite nanofibers of polyurethane and catalytically active Pd-or Cu-functionalized poly(amido amine) dendrimers were electrospun and subsequently coated with poly(p-xylylene) by the chemical vapor deposition. After removal of the inner polyurethane template matrix, the dendrimers remained encapsulated inside the confinement and the leaching behavior of the caged dendritic catalysts was studied. The tube system was successfully used as a readily reusable tea bag type catalyst for Suzuki−Miyaura couplings and alkyne/azide click reactions.